Credentials include identification cards, driver's licenses, passports, and other documents. Such credentials are formed from credential or card substrates including paper substrates, plastic substrates, cards and other materials. Such credentials generally include printed information, such as a photo, account numbers, identification numbers, and other personal information. Credentials can also include data that is encoded in a smartcard chip, a magnetic stripe, or a barcode, for example.
Credential production devices process credential substrates by performing at least one processing step in forming a final credential product. One such process is a transfer or lamination process that transfers a material to a surface of the card substrate using a heated transfer roller of a transfer unit of the device. This process can be used to transfer an image to the surface of the card substrate and/or provide protection to the surface of the card substrate from abrasion and environmental conditions, for example.
Intermediate transfer films or transfer ribbons include a fracturable laminate or transfer layer, which is often referred to as a “thin film laminate,” that can be transferred to a surface of a card substrate using the heated transfer roller. Such transfer layers are generally continuous resinous materials that have been coated onto a continuous carrier layer or backing to form a transfer ribbon. The side of the resin material that is not attached to the continuous carrier layer is generally coated with a thermal adhesive which is used to create a bond between the resin and the surface of the substrate. The transfer roller is used to thermally activate the adhesive and press the resinous material against the surface of the substrate to bond the material to the surface. The carrier layer or backing is removed to complete the lamination process.
The transfer layer may also be in the form of a print intermediate, on which an image may be printed in a reverse-image printing process. In the reverse-image printing process, a print head is registered with a transfer section of the transfer layer, and an image is printed to the transfer section using the print head. Next, the imaged transfer section is registered with the card substrate and/or the transfer roller. The transfer roller is then used to activate the adhesive of the imaged transfer section causing the imaged transfer section to bond to the surface of the card substrate. The carrier layer or backing of the overlaminate material is then removed from the bonded imaged transfer section to complete the transfer of the image to the card substrate.
FIG. 7 is a simplified top plan view of an intermediate transfer film or transfer ribbon 700 in accordance with the prior art. The conventional transfer ribbon 700 includes black registration or alignment marks 702 that are used by the credential production device to register the transfer sections 704 of the transfer layer to the print head, card substrate and/or transfer roller. The registration process generally involves detecting the marks 702 using an optical sensor as the ribbon 700 is fed relative to a component of the device, such as the print head, the transfer roller, or the substrate. Typically, a transfer section 704 is registered with the desired component upon detection of one of the marks 702.
The marks 702 generally comprise a black resin or other black material that is printed to the transfer ribbon 700. The marks 702 are located outside the boundaries of the transfer sections 704 to prevent the marks 702 from transferring to the substrate during the transfer or lamination process, which would produce undesirable marks on the substrate. As a result, the width 706 of the ribbon 700 must be made sufficiently wide to accommodate both the marks 702 and the transfer sections 704. This results in significant waste of the transfer layer, as at least the portion 708 of the transfer ribbon 700 along the lengthwise boundary of the transfer sections 704 is never used.
The transfer ribbon 700 is slightly thicker at the locations of the marks 702 due to the thickness of the marks 702. When the transfer ribbon 700 is wound on a spool, the marks 702 cause a thicker ridge to form on one side of the spool. This can cause uneven tension in the transfer ribbon 700 as it is unwound from a supply spool, or wound onto a take-up spool of the credential production device. As a result, the transfer ribbon 700 is prone to wrinkling during use in the credential production device, which can adversely affect the quality of the image that is transferred to the substrate.